Casting roll for a two-roll continuous casting installation

Abstract

A casting roll of a two-roll continuous casting installation is to be able to be exposed to a changing temperature stress and roll pressures when casting strip made of non-ferrous metals, especially of aluminum or an aluminum alloy. For this purpose, its sleeve is made of an age-hardening copper alloy made of—as expressed in each case as weight %—0.4% through 2% cobalt, which is partially exchangeable for nickel, 0.1% through 0.5% beryllium, optionally 0.03% through 0.5% zirconium, 0.005% through 0.1% magnesium and possibly a maximum of 0.15% of at least one element of the group including niobium, manganese, tantalum, vanadium, titanium, chromium, cerium and hafnium, the remainder being copper and inclusive of manufacturing-conditioned impurities and usual processing additives.

What is claimed is:  
     
         1 . A casting roll for a two-roll continuous casting installation which, during the casting of strips made of non-ferrous metals, undergoes changing temperature stress and high roll pressures, comprising a sleeve made of an age-hardening copper alloy, which includes in weight %: 0.4% through 2% cobalt, which may be partially substituted with nickel, 0.1% through 0.5% beryllium, and a remainder of copper.  
     
     
         2 . The casting roll according to  claim 1 , in which the copper alloy further includes 0.03% through 0.5% zirconium and 0.005% through 0.1% magnesium.  
     
     
         3 . The casting roll according to  claim 1 , in which the copper alloy further includes a maximum of 0.15% of at least one element selected from the group consisting of niobium, manganese, tantalum, vanadium, titanium, chromium, cerium and hafnium.  
     
     
         4 . The casting roll according to  claim 2 , in which the copper alloy contains 0.03% to 0.35% zirconium and 0.005% to 0.05% magnesium.  
     
     
         5 . The casting roll according to  claim 2 , in which the copper alloy contains less than 1.0% cobalt, 0.15% through 0.3% beryllium and 0.15% through 0.3% of zirconium.  
     
     
         6 . The casting roll according to  claim 1 , in which the copper alloy has a ratio of cobalt to beryllium of between 2 and 15.  
     
     
         7 . The casting roll according to  claim 2 , in which the copper alloy has a ratio of cobalt to beryllium of between 2 and 15.  
     
     
         8 . The casting roll according to  claim 3 , in which the copper alloy has a ratio of cobalt to beryllium of between 2 and 15.  
     
     
         9 . The casting roll according to  claim 6 , in which the copper alloy has a ratio of cobalt to beryllium of between 2.2 and 5.  
     
     
         10 . The casting roll according to  claim 1 , in which the copper alloy further includes up to 0.6% nickel in addition to cobalt.  
     
     
         11 . The casting roll according to  claim 2 , in which the copper alloy further includes up to 0.6% nickel in addition to cobalt.  
     
     
         12 . The casting roll according to  claim 2 , in which the copper alloy further includes a maximum of 0.15% of at least one element selected from the group consisting of niobium, manganese, tantalum, vanadium, titanium, chromium, cerium and hafnium.  
     
     
         13 . The casting roll according to  claim 1 , wherein the sleeve is produced by casting, hot working, solution treatment at 850° C. to 980° C., cold working up to 30% as well as age-hardening at 400° C. to 550° C. within a time period of 4 to 32 hours, the sleeve having a maximum average grain size of 1.5 mm as per ASTM E 112, a hardness of at least 170 HBW, and an electrical conductivity of at least 26 Sm/mm 2 .  
     
     
         14 . The casting roll according to  claim 13 , in which the sleeve, in the age-hardened state, has an average grain size of 30 μm to 500 μm as per ASTM E 112, a hardness of at least 185 HBW, a conductivity between 30 and 36 Sm/mm 2 , a 0.2% yield strength of at least 450 MPa and an elongation at break of at least 12%.  
     
     
         15 . The casting roll according to  claim 1 , in which the sleeve is provided with a coating that reduces the permeability to heat.  
     
     
         16 . The casting roll according to  claim 15 , in which the coating has a great surface hardness.  
     
     
         17 . The casting roll according to  claim 1 , in which the surface is designed to be smooth.  
     
     
         18 . The casting roll according to  claim 1 , in which the surface is textured.  
     
     
         19 . The casting roll according to  claim 18 , in which a substance is embedded in the depressions, formed by the texturing, which has a low heat conductivity compared to the heat conductivity of copper.